backinblue92

iTrader: (1)

I did a compression test and cyl 1 and 4 put up 230 and 235, respectively, but cyls 2 and 3 put up 200 and 210. I have no oil in the coolant or vice versa and having just done the timing belt, the timing is dead on and the engine pulls better than it ever has. There's no smoke other than the white smoke on a cold morning. Could there be a chance my head gasket between 2/3 is cracked but not all the way out to the oil and coolant passages? Or any other thought on what it could be?

I plan on a leak down test soon just as a precaution but at the moment I'm not worried.. Just curious what the cause could potentially be. Thanks!

Edit: my buddy wasn't holding the throttle open and I wasn't pressing the gas because I though he had already blocked the throttle plate open.. So I guess these numbers don't really mean anything. I'll update if they're out of line on the next test.

Gunmetalbb6

probably a good bet its a head gasket...

holmesnmanny

No.

backinblue92

iTrader: (1)

holmesnmanny:

First off, I wanted to apologize to you for being rude a couple weeks back in that timing belt thread I was working on. It was a frustrating experience.

Onto the question:
No to possible head gasket issue or was that to the person suggested head gasket? I haven't had a chance to retest the compression; been busy doing a minor makeover on the exterior (I'm kinda upset those Depo? JDM 1-pc knockoffs that had the amber corners aren't in production anymore)

Anyways. As I understand it compression numbers without the throttle wide open are basically only testing the vacuum capacity of each cylinder, not the actual compression of the cylinder, correct?

I mean, if I were to operate under the assumption the numbers could be legit even with the throttle plate closed, that the two center cylinders which both run on the same stroke could have just over 10% variance from the outer cylinders would be puzzling, considering there is no oil or coolant mixed. It would make me think there is a very minor compression leak due to head gasket (barring some sort of freak occurrence of perfectly aligned wear of two separate cylinders)

PS- I also noticed a couple odd, intermittent issues recently. When the engine is hot (hot day, running errands, traffic) once in a while it will turn over like 8 times before starting/will start then die. Turn the key again, starts up with no issue.

And in the same conditions (hot day/stop and go traffic), it's close to guaranteed and ONLY with the A/C on that the clutch will slip under heavier acceleration. By slip I mean it will feel pretty heavy upon release, and pedal will release much slower than usual. Clutch is nearly brand new. 10k miles. Flywheel and clutch plate were replaced when I did the job. And its only recently this popped up too.

Thanks for any advice/thoughts/trolling lol anybody cares to share.

snobordboy

For my thoughts...

Compression test - re-do it properly and just end any specualtion, doesn't take that long.

Hot start issue - failing main relay, either re-solder it or replace it. I keep a good spare in my car at all times.

Clutch issue - Doesnt sound like slip, sounds like either fluid issues in the line and it needs to be bled, or you need a higher temp grease on the pivot arm and shaft.

backinblue92

iTrader: (1)

Yeah I'll just redo the compression test and know for sure.

Hot start issue- thanks, will look into that. A quick search absolutely confirms your thoughts there. I feel stupid. Haha.

Clutch issue is a little more intensive though. While I do think there is a fluid issue- if I jack the car up from the front overnight, the clutch will feel stronger the next day- I took it out today and checked it out. Went through some stop/go traffic in 70* weather with A/C on, then got up to crusing speed, now with the A/C on or off doesn't matter, when I gun the engine the rpm will spike almost like its in neutral when I was really in 5th and the car lagged then it'll "catch up to itself". Pull off the freeway, let it cool down for a half hour, and all is normal again. This may be important: These two things go hand in hand. The heavy clutch feel only occurs when the clutch feels like its slipping.

I think you're right that the fluid plays a role in why the clutch can feel really heavy upon disengagement (maybe condensation in the line, maybe I didn't get all the air out of the master initially, maybe there's a leak in the master or slave), but any grease/fluid issue wouldn't affect the rpm slipping when its not engaged, would it? Yet my slip/heavy clutch issue only happen together. Or am I not understanding something? I did the job myself, took me 2 weeks as I'd never dropped a tranny before..I learned a lot, that's how we fix our cars, even if it takes us a while, haha. So any further knowledge you can drop would be appreciated. I don't want to just fix it. I want to know why its happening too.

holmesnmanny

Around 10% variance is normal.

backinblue92

iTrader: (1)

Redid compression test WOT and here's the results (order is pass side to driver) 250, 250, 205, 250. So cylinder 2 is low. Redid test with a little oil in cylinder, no change. Good thing I suppose? Means my rings are all good. Leakdown test the next step? Or should I do a valve adjustment first and see if that takes care of it before I look at valve seals?

So overall, my numbers are a little high, which from research would lead me to believe it could be carbon deposits?

I do not know much of individual cylinder compression variation. Any help highly appreciated. Thanks!

ojasia

Replace Clutch master cylinder. Same thing was going on with mine, you need a leak down test. when I finally swapped my new engine in I had to re-use my cylinder head and with it having 140k the valve seats were pitted/carbon messes, the valves were just corroded with 1/8 of dry dusty carbon and gunk. valve adjustment wont fix a leaky seat.

Valve seals wont raise your compression either, seeing as on the compression stroke the seals should not see compression cause the valves would be closed during most of the compression stroke event. There made to keep a thin film of oil on the stem not keep compression in.